Sri Kunarti, Eko, and Grainne Moran. “Effect of Glycerol on the Activity of a-Chymotrypsin Encapsulated in Sol-Gel Derived Silica Monoliths”. Asian Journal of Chemistry, vol. 23, no. 9, June 2011, pp. 3940-4, https://asianpubs.org/index.php/ajchem/article/view/10765.